 The Secret of the Lost Tunnel by Franklin W. Dixon |  The Clue of the Screeching Owl by Franklin W. Dixon |  No Way Out by Franklin W. Dixon |  Danger on Vampire Trail by Franklin W. Dixon |  The Wailing Siren Mystery by Franklin W. Dixon |  The Clue of the Broken Blade by Franklin W. Dixon |  The Phantom Freighter by Franklin W. Dixon |  The Mystery of the Spiral Bridge by Franklin W. Dixon |  The Witchmaster's Key by Franklin W. Dixon |  The Haunted Fort by Franklin W. Dixon |  The Arctic Patrol Mystery by Franklin W. Dixon |  The Jungle Pyramid by Franklin W. Dixon |  The Secret Agent on Flight 101 by Franklin W. Dixon |  The Shattered Helmet by Franklin W. Dixon |  The Mystery of the Desert Giant by Franklin W. Dixon |  The Masked Monkey by Franklin W. Dixon |  The Viking Symbol Mystery by Franklin W. Dixon |  The Sign of the Crooked Arrow by Franklin W. Dixon |  A Figure in Hiding by Franklin W. Dixon |  The Twisted Claw by Franklin W. Dixon |